🚀 go-pugleaf

I hope to get your help as a registered EndNote Plus 2 user.

I'm using the EndNote plug-in module with Word 5.1a on a Mac computer.

I'm trying to format references in a manuscript for Science magazine.
 How do I put several journal citations under one reference number?  
For example:

(1) M. D. New, Cell 47, 205 (1986);  V. Old, Nature 266, 705 (1995).

I insert M. D. New and V. Old by highlighting both from the bibliography and 
insert them in the manuscript.  Then, when formatting, Endnote assigns 
consecutive reference numbers (1 and 2) to M. D. New and V. Old. 
How do I have only one number (1) assigned to both references?

Thank you!

William McClain